Bug Summary

File:src/lib/libm/src/s_ctanl.c
Warning:line 146, column 3
Value stored to 'd' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name s_ctanl.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/lib/libm/obj -resource-dir /usr/local/lib/clang/13.0.0 -include namespace.h -I /usr/src/lib/libm/arch/amd64 -I /usr/src/lib/libm/src -I /usr/src/lib/libm/src/ld80 -I /usr/src/lib/libm/hidden -D PIC -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/lib/libm/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/lib/libm/src/s_ctanl.c
1/* $OpenBSD: s_ctanl.c,v 1.3 2011/07/20 21:02:51 martynas Exp $ */
2
3/*
4 * Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19/* ctanl()
20 *
21 * Complex circular tangent
22 *
23 *
24 *
25 * SYNOPSIS:
26 *
27 * long double complex ctanl();
28 * long double complex z, w;
29 *
30 * w = ctanl( z );
31 *
32 *
33 *
34 * DESCRIPTION:
35 *
36 * If
37 * z = x + iy,
38 *
39 * then
40 *
41 * sin 2x + i sinh 2y
42 * w = --------------------.
43 * cos 2x + cosh 2y
44 *
45 * On the real axis the denominator is zero at odd multiples
46 * of PI/2. The denominator is evaluated by its Taylor
47 * series near these points.
48 *
49 *
50 * ACCURACY:
51 *
52 * Relative error:
53 * arithmetic domain # trials peak rms
54 * DEC -10,+10 5200 7.1e-17 1.6e-17
55 * IEEE -10,+10 30000 7.2e-16 1.2e-16
56 * Also tested by ctan * ccot = 1 and catan(ctan(z)) = z.
57 */
58
59#include <complex_Complex.h>
60#include <float.h>
61#include <math.h>
62
63#if LDBL_MANT_DIG64 == 64
64static const long double MACHEPL= 5.42101086242752217003726400434970855712890625E-20L;
65#elif LDBL_MANT_DIG64 == 113
66static const long double MACHEPL = 9.629649721936179265279889712924636592690508e-35L;
67#endif
68
69static const long double PIL = 3.141592653589793238462643383279502884197169L;
70static const long double DP1 = 3.14159265358979323829596852490908531763125L;
71static const long double DP2 = 1.6667485837041756656403424829301998703007e-19L;
72static const long double DP3 = 1.8830410776607851167459095484560349402753e-39L;
73
74static long double
75redupil(long double x)
76{
77 long double t;
78 long i;
79
80 t = x / PIL;
81 if (t >= 0.0L)
82 t += 0.5L;
83 else
84 t -= 0.5L;
85
86 i = t; /* the multiple */
87 t = i;
88 t = ((x - t * DP1) - t * DP2) - t * DP3;
89 return (t);
90}
91
92static long double
93ctansl(long double complex_Complex z)
94{
95 long double f, x, x2, y, y2, rn, t;
96 long double d;
97
98 x = fabsl(2.0L * creall(z));
99 y = fabsl(2.0L * cimagl(z));
100
101 x = redupil(x);
102
103 x = x * x;
104 y = y * y;
105 x2 = 1.0L;
106 y2 = 1.0L;
107 f = 1.0L;
108 rn = 0.0L;
109 d = 0.0L;
110 do {
111 rn += 1.0L;
112 f *= rn;
113 rn += 1.0L;
114 f *= rn;
115 x2 *= x;
116 y2 *= y;
117 t = y2 + x2;
118 t /= f;
119 d += t;
120
121 rn += 1.0L;
122 f *= rn;
123 rn += 1.0L;
124 f *= rn;
125 x2 *= x;
126 y2 *= y;
127 t = y2 - x2;
128 t /= f;
129 d += t;
130 }
131 while (fabsl(t/d) > MACHEPL);
132 return(d);
133}
134
135long double complex_Complex
136ctanl(long double complex_Complex z)
137{
138 long double complex_Complex w;
139 long double d, x, y;
140
141 x = creall(z);
142 y = cimagl(z);
143 d = cosl(2.0L * x) + coshl(2.0L * y);
144
145 if (fabsl(d) < 0.25L) {
146 d = fabsl(d);
Value stored to 'd' is never read
147 d = ctansl(z);
148 }
149 if (d == 0.0L) {
150 /*mtherr( "ctan", OVERFLOW );*/
151 w = LDBL_MAX1.18973149535723176502e+4932L + LDBL_MAX1.18973149535723176502e+4932L * I1.0fi;
152 return (w);
153 }
154
155 w = sinl(2.0L * x) / d + (sinhl(2.0L * y) / d) * I1.0fi;
156 return (w);
157}